fix(HEL-190): 按真实交易日历补齐最近60日快照，修复断档后只显示当天

保留连续性过滤，新增可审计补档工具与备份步骤；周末/节假日与真缺档分开处理，支持重复执行与部分失败续跑。

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

backend/features/system/routes.py

@@ -29,11 +29,17 @@ class SystemRoutesMixin:
     def backfill_data(self) -> None:
         try:
             body = self.read_json_body()
-            results = self.application_service.backfill(
+            lookback_raw = body.get("lookback")
+            lookback = int(lookback_raw) if lookback_raw not in (None, "") else None
+            audit = self.application_service.backfill(
                 str(body.get("start_date") or ""),
                 str(body.get("end_date") or ""),
+                lookback=lookback,
+                dry_run=bool(body.get("dry_run")),
+                force=bool(body.get("force")),
+                create_backup=body.get("create_backup", True) is not False,
             )
-            self.send_json({"ok": True, "results": results})
+            self.send_json({"ok": True, **audit, "results": audit.get("results") or []})
         except ValueError as exc:
             self.send_json({"error": str(exc)}, HTTPStatus.BAD_REQUEST)
         except Exception as exc: